How many deck boards for a 10×10 deck?
Quick Answer
A 10×10 foot deck (100 sq ft) requires approximately 20 boards of 5/4×6×10 decking (10-foot boards across 10-foot span) or 14 boards of 5/4×6×12 laid in the other direction. With 10% waste, order 22–25 boards. This is for decking only — add rim boards, joists, and posts separately.
Quick Reference Table
| Board size | Deck boards for 10×10 deck |
|---|---|
| 5/4×6×10 (run parallel) | 20 boards + 10% = 22 |
| 5/4×6×12 | 14 boards + 10% = 16 |
| 2×6×10 (thicker) | 20 boards + 10% = 22 |
| Composite 1"×6×12 | 14 boards + 10% = 16 |
How to Calculate It Yourself
- 1
Determine the deck area: 10 × 10 = 100 sq ft.
- 2
A 5/4×6 board has a nominal 6" width; actual face width is 5.5".
- 3
With 1/8" gap between boards, effective width per board = 5.625".
- 4
For 10 ft span: 120" ÷ 5.625" = 21.3 → 22 boards.
- 5
Add 10% for waste and end cuts: 22 × 1.10 = 25 boards.
Pro Tip
Buy boards in the longest length that avoids a seam on your deck surface. Seams on deck boards are a common weak point — full-length boards with no butt joints are stronger and look better.
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